In general, magnetic recording discs can be classified as of the rigid and the flexible or non-rigid type, with the predominance being toward the rigid type which generally comprises a magnetizable coating or surface placed on a rigid plate or platter. Various suggestions have been made for flexible recording discs, but in general these have been of a type where the flexible material was mounted or fastened to a more rigid platter or plate, and various arrangements were provided to move the flexible magnetic disc at some point on its surface toward a magnetic transducer.
The rigid recording discs are expensive and are subject to damage due to "crashes" when the transducer accidentally makes heavy enough contact with the surface so as to mar or scratch the surface, thereby destroying the magnetizable coated surface. Furthermore, it is difficult and expensive to provide such discs which run true in a plane, and continue to do so when exposed to changing conditions of temperature and/or humidity, and which have a uniform magnetizable coating thereon. The mounting and handling of flexible magnetic recording discs has been given little attention. There has been little or no progress in interchangeability of such discs, with the attendant problems of concentricity, proper tracking, and proper interfacing between the transducer and the recording surface of the disc. On the other hand, there is a need for a relatively inexpensive, but accurate, magnetic disc recorder, and particularly recording disc units which are inexpensive to manufacture, but still accurate enough to achieve high fidelity recording, preferably with bandwidth sufficient to record and reproduce video information, for example, in the order of 2 to 4 MHz. bandwidth.